Dear M. Nair,
In nutshell, a Partnership firm governs by the provisions of Indian Partnership Act while there is no governing law for proprietorship [ concern] firm. It is misnomer that some time we use the word ' firm' for both the entities. Actually for proprietorship the word 'concern' is used in legal terminology intsead of the word 'firm'.
There has to be atleast two partners in the Partnership firm. A proprietorship concern is run by one man only with his business name Like M/s Ramchet & Sons etc. proprietor Mr. Ramchet. Hope this will satisfy yr query
regards